ILLUSTRATIONS BY ALEX WILLIAMSON

In the salle des assises, the Paris courtroom reserved for the examination of murders, rapes, and other serious crimes, a box of thick glass has been erected atop the old wood enclosure in which the accused is made to sit. The glass is a recent addition, and incongruous; the remainder of the room—the lustrous carved oak of the wainscoting, the six brass chandeliers strung from the high plafond—has been preserved as it was at least a century and a half ago. Above the glass box, a grand mural depicts a conclave of red-robed judges and the child king Louis XIII. The mural is in fact a somewhat recent flourish, having been commissioned by the wartime fascists of Vichy, but that infelicitous detail is easily obscured by the vision of splendid continuity the painting sets forth. French judges still wear those red robes. Amid this pomp, the effect of the glass box is that of nothing so much as a museum specimen case, one intended for curiosities of human scale.

Last year, for the month of October, it held a 35-year-old Franco-Algerian man named Abdelkader Merah. More than five and a half years had passed since the crimes of which he was accused—long waits in prison are common in French terrorism cases—but in that time, by a tragic paradox, the expectation that his trial might generate insights of immediate use to the country had only grown. Merah was a jihadist of the sort to which France and Europe have lately grown accustomed, a “homegrown” criminal-turned-radical, an “Islamo-delinquent” whose local resentments and fantasies of violence found justification and structure in a vicious Islam. He was charged as an accomplice in the killings that first brought such men to the attention of France, and arguably, the world. A conviction could send him to prison for life.

On the afternoon of March 11, 2012, in the corner of an empty parking lot in Toulouse, gendarmes had discovered the lifeless body of an off-duty airborne commando. The victim, a Franco-Moroccan, had been shot in the face. Witnesses reported seeing the presumptive killer flee the scene aboard a large motor scooter. Four days later, in Montauban, 30 miles north, a shooter ambushed three soldiers outside their barracks. Two of the men died; the third was left paralyzed. All three victims had been dressed in green military fatigues; two were of Algerian descent, and the other black. Witnesses again described an assailant fleeing on a motor scooter, and ballistics confirmed that the same .45 caliber pistol had been used in both shootings. In Paris, intelligence officials surmised that the killer was a racist ultranationalist, perhaps a former soldier with a grudge against the military that converged with his hatred of nonwhites.

The murders four days later clarified matters. That day, shortly before eight o’clock in the morning, the killer arrived outside a Jewish school on a narrow residential street in Toulouse and opened fire on a group of small children arriving for the day, alongside a young rabbi. He sprayed them with fire from an Uzi submachine gun; when it jammed, he pulled a Colt .45 from his pocket and stood over his victims to execute them from close range. The four dead were an 8-year-old girl; the rabbi, 30; and his two sons, ages 5 and 3. Once again the shooter escaped on a motor scooter.

The killings, the country soon discovered, were the work of Abdelkader Merah’s 23-year-old younger brother, Mohammed. Before dying in a shootout with police three days after the last of the murders, Mohammed declared himself a member of Al Qaeda. He’d targeted the soldiers, he said, because their units had been deployed to Afghanistan, where they fought the Taliban; the Jewish children were revenge for the daily “massacre” of Palestinians.

Mohammed became the hero of a generation of French jihadis, who still hail him in their propaganda as a “lion” who showed the way. French authorities, meanwhile, believed that Abdelkader had been his mentor. Together, in the words of the charging document in Abdelkader’s case, the Merah brothers were the “new face of terrorism.” French jihadists of previous eras traveled to the faraway lands of Islamic lore to fight; the new ones murdered their neighbors.

To say the Merah killings “shocked” France would be misleading, in addition to being obvious. Certainly they inaugurated a new and ongoing political moment, one in which the French came to view domestic jihadism as “the greatest challenge of our generation,” to quote one recent prime minister. But the killings were widely experienced less as a surprise than as a strange sort of vindication, a validation of cultural anxieties that had for years coursed just beneath the surface of French political debate: the alleged unwillingness of French Muslims to submit to the norms of French republicanism; the perceived ultraviolence of the young black and Arab postcolonial Frenchmen of the banlieues; and a feeling that those banlieues, under the sway of violence and Islam, were slipping out from the control of the République much as its overseas colonies once had.

The Merah killings were experienced less as a surprise than as a vindication, a validation of cultural anxieties that had long coursed beneath the surface of French political debate.

Mohammed committed his murders in the final weeks of France’s presidential campaign. Shortly after the killings, Nicolas Sarkozy, the right-wing incumbent, published a “Letter to the French” in which he rehashed the “clash of civilizations” hypothesis, positing Mohammed as an ideologue first and foremost, a killer at the vanguard of an intellectual movement “that is working for the destruction of the values of the West.” “We must combat the criminal manifestations of this ideology of hate,” he wrote. “But we must also fight it at its intellectual root, in the prisons, in the sermons of some extremist preachers, and also on internet sites.”

Sarkozy lost the election, but official France adopted his view of contemporary jihadism. The French have had several decades of experience with jihadism, but prior to the Merah killings they treated it almost exclusively as a matter of law enforcement, Peter Neumann, a political scientist at King’s College and prominent scholar of political violence, told me. “For a long time, they resisted talking about radicalization,” Neumann said. “They thought it was an Anglo-American conspiracy.” The French maintained that they were engaged in the prevention of violence, and it was the violence that mattered; whatever system of thought may have led to it was not, in a liberal democracy, a legitimate matter for state intervention. After the Merah killings, this stance came to be seen as dangerously naïve. Ideas were at the root of Mohammed’s violence, the new thinking went, and if violence such as his were to be stopped, the French would have to confront the ideas and their transmission more directly. Jihadism was no longer a mere matter of law enforcement, but a battle in an existential war of culture.

After Merah, new laws banned the French from visiting jihadi websites or making “apologias for terrorism.” Citizens identified as “radicalized” were banned from leaving the country; the government spent hundreds of millions of euros developing “de-radicalization” programs. (The programs were voluntary, and, unfortunately, of little interest to their target population.) In November 2015, after the attacks in Paris that left 130 dead, which had themselves followed the murders at the satirical newspaper Charlie Hebdo earlier that year, the government declared a state of emergency. The security services were authorized to unilaterally place suspected radicals under indefinite house arrest, and to raid their homes without judicial warrants. Mainstream politicians spoke of creating internment camps for the 10,000 “radicalized” people flagged by the counter-terrorism authorities. By the logic that the Merah killings had ushered in, their alleged radicalization was effectively a crime in itself.

Abdelkader had been arrested in 2012 in a France that acknowledged, however uncomfortably, his right to whatever despicable beliefs he might harbor. The country in which he would be judged, altered as it was by his brother’s attacks and by the many that followed, did not. The trial was deemed by French officials and the press to be a moment of “national catharsis,” the redemptive coda to a cycle of national suffering. It was also the occasion to evaluate the new paradigm, the new theory of the evil afflicting France, by applying it to the very men who were at its origins. “Abdelkader Merah created Mohammed Merah,” the public prosecutor would claim. The two had functioned as a unit, “the one who played the role of sage, the other who played the role of combatant.” The prosecution held that Abdelkader had radicalized his brother, had provided him with the beliefs that were evidently the cause of his violence, and on its face this seemed a perfectly reasonable claim.

Mohammed Merah first went before a court at the age of 13. By the age of 20, he had been tried for and convicted of several thefts, a handful of assaults, and various other minor crimes. It was in prison, where he served less than two years, that he appears to have taken up Islam. He came to be known as a member of what French security officials called Toulouse’s “Salafist faction,” a loose group of about 100 Muslim fundamentalists who were monitored by the domestic intelligence service, known at the time as the DCRI. (After the Merah killings, the service was restructured and renamed.) Mohammed traveled widely in the Middle East, and made monthlong trips to both Afghanistan and Pakistan. Still, the DCRI viewed him to be, in the words of one declassified intelligence report, “an ambiguous character.” He seemed to be attempting to lead the pious and watchful life of a would-be jihadi operative, but then proving incapable of the requisite discipline. In Toulouse, he never used a cell phone registered in his name, and he stopped his car to pray at the roadside at the appointed hours. But he also drove donuts, sped wildly on the road, and had bloody fistfights in Les Izards, his childhood neighborhood. Once, he had taken a young local boy into his apartment, locked the door, and forced him to watch videos of decapitations and other jihadist violence; the boy’s mother filed a complaint with the police.

Abdelkader, six years older, was known to be less volatile. He too had been a petty criminal, but he seemed to have left that life behind more completely. He attended Koranic schools in Egypt, and the DCRI understood him to be an intellectual force within the small world of Toulousain jihadism.

Abdelkader had been arrested in a France that acknowledged his right to whatever despicable beliefs he might harbor. The country in which he would be judged did not.

Within hours of the killings at the Jewish school, both Merah brothers had been identified as suspects. In the early hours of March 21, 2012, police commandos moved to arrest them, at their separate homes. Mohammed opened fire on them and was subsequently shot and killed. Fifteen miles south, the men who smashed through the door of Abdelkader’s home found him in the living room, where, as if to aid in confirming his identity, he had left his passport on a countertop. “I was expecting a visit from the police,” he said later.

He denied any involvement in the killings. “I wasn’t my little brother’s accomplice in anything,” he told investigators. “If I shared the same religious convictions as him, I’d have participated in his actions, and if he’d told me about his plans, I’d have strongly dissuaded him.” But he applauded Mohammed’s actions just the same. “I’m proud of their aim,” he said. “Every Muslim would like to be killed by his enemy.” Mohammed had died “like a lion,” he said, “and not like a mouse.”

Abdelkader vacillated between what seemed a bizarre forth-rightness and a posture of coy and improbable ignorance. He volunteered, unprompted, that he had been present for the theft of the scooter that Mohammed used in the killings, and told investigators that, a few weeks prior, his brother had spoken to him of waging jihad in France. “He was telling me that our Muslim brothers were under attack from the crusaders everywhere in the world,” Abdelkader recalled. “I told him that this was true, but that Islam isn’t applied with passions and hate but according to the texts.” Abdelkader told investigators: “If it’s a crime to be named ‘Merah,’ I’m guilty; if it’s a crime to be Muslim, I’m guilty; if it’s a crime to be for jihad, with the rules that go with it, I’m guilty.”

He would be tried by a tribunal of professional magistrates. The six of them sat atop the elevated bench at the front of the salle des assises, each faintly illuminated by the glow of a brass banker’s lamp and dressed in black robes and a frilly white kerchief, with the exception of the chief magistrate, known as the president, who sat in the center in red. In addition to the prosecution and the defense, French trials accord a prominent role to the victims of a crime. In the Merah case, 232 people had registered as plaintiffs, mostly the families and extended families of the victims; their two dozen lawyers sat beneath the president, aligned in three rows like a panel of black-robed inquisitors. From across a narrow space at the center of the court they faced the glass cage.

Abdelkader entered the box each day through a rear door, with a lumbering nonchalance. The mug shot that had been provided to the press, evidently from his pre-Islamic years, portrayed a hard and contemptuous man, but he had grown chubby in prison and now radiated a smug detachment more than violence. His belly strained at the lower buttons of a white dress shirt. He wore a librarian’s reading glasses, held with a lanyard around his neck, and a long black beard ran from his temples to his chin, framing a pale, almost perfectly round, oddly cherubic mien. His mustache was freshly shaved, in the style favored by Salafis. He sat at the front of the glass box with his head cocked slightly back off his shoulders, quietly posturing, it seemed, like both the gangster he’d once been and the Muslim zealot he’d become.

As a child in Les Izards, he was reputed to be particularly violent. “Abdelkader feels no limits, acknowledges no laws,” a social worker wrote of him at 14. He beat his mother and was sent to prison for stabbing his elder brother, Abdelghani, seven times in the side. He visited Algeria during its civil war in the 1990s; according to Abdelghani, who survived the stabbing and testified against his brother at the trial last year, Abdelkader was entirely unfazed by the corpses piled in the streets. After the attacks of September 11, 2001, he came to be known in Les Izards as “Ben Ben,” after Osama bin Laden, whose ascetic religious doctrine was then of no interest to him—he went to prostitutes, drank alcohol, snorted cocaine, and smoked hashish, which he apparently also sold—but whose grand spectacle of murder evidently was. In his mid-20s, for reasons he could not or would not articulate to the court, except to speak of a “sadness of heart,” he put an end to his old ways. “From there on out, I changed,” he said. “I didn’t even steal a bonbon.” Abdelkader called himself an “orthodox Muslim,” and said that, though he was born into the faith, he had “converted” to the true Islam.

Various members of the Merah family were called to the stand to testify to his influence over Mohammed. “Through his example, through his words, through his hate,” Abdelghani said of him, “he made Mohammed into a terrorist.” As a young man, Abdelghani had been extremely violent himself, though he had never been drawn to Islam. “What I know is that Abdel’s violence brought on Kader’s violence,” their sister, Aïcha, testified. “And Kader’s violence brought on Mohammed’s violence.”

Abdelkader’s posture fluctuated, as it had during the investigation, between quiet defiance and obfuscation and self-satisfied provocation. “What do you think of the French soldiers who join up to go fight in Afghanistan?” a plaintiff’s attorney asked at one point. “I don’t do geopolitics,” he said, turning to the presiding judge. “I don’t know what’s happening in Afghanistan.”

Another attorney asked, “What is a martyr?”

“There are several types of martyr in Islam,” Abdelkader replied.

“And Mohammed Merah, did he die a martyr?”

“Ah, that, I don’t know,” he said, throwing up his hands. “No one can know.”

As it happened, Abdelkader had been recorded, in a jailhouse conversation with his mother, describing Mohammed’s glorious martyr’s life in paradise. The lawyer proceeded to read aloud from the transcript: “He’s got the houris now,” Abdelkader had said, referring to the young virgins reserved for Islamic martyrs. “Right now he’s not in his tomb, he’s in heaven.” “Ah, he has the houris with him?” his mother asked. Abdelkader replied, “He has the houris, he’s doing the shameful act with them, he’s doing everything!”

He and Mohammed had in fact not been reputed to get along, and it appeared the two had not spoken for nearly the entire year before the killings. Yet in the month immediately prior to the attacks, and during their nine-day span, the brothers saw one another repeatedly. Abdelkader claimed that he had sought Mohammed out to resolve their differences, as the Koran recommends. The prosecution contended that their estrangement had been a feint, a way to throw the authorities off the trail of their conspiracy, and that they had staged a reconciliation to put the final touches on their plot.

It was almost impossible to imagine that Abdelkader had not somehow participated in his brother’s murders. Stated in general terms, the facts of the case were that two brothers, members of a cultish, ultra-minority sect, were repeatedly seen together during the period when one of them was committing a series of murders in the name of precisely the rare beliefs they happened to share. The truly extraordinary thing would have been if Abdelkader were not involved.

Clockwise from top: Abdelkader Merah was tried at the Palais de Justice in Paris; His mother, Zoulikha Aziri, testified on his behalf; this photo of Mohammed Merah, taken before the murders, was widely seen throughout France; a courtroom sketch of Abdelkader.

The most readily identifiable shortcoming of the case against Abdelkader was the near-complete lack of material evidence to prove it. The prosecution advanced no proof that Abdelkader had helped his brother to procure the weapons he used or to choose his victims, or to plan the attacks, or to finance them, or to produce and distribute the video in which Mohammed claimed responsibility. The best they’d found, the element that served as the crux of the prosecution’s case, was Abdelkader’s avowed participation in the theft, five days before the killings began, of the Yamaha TMAX 530 motor scooter that Mohammed rode to and from the murders. On the afternoon of the tenth day of the trial, the president asked Abdelkader to describe the incident to the court.

Abdelkader, Mohammed, and a third man—Abdelkader had always refused to name him, to protect him from being “unjustly incarcerated” like himself—had been driving through an industrial park on the outskirts of Toulouse, when Mohammed started to yell from the back seat. “My brother says, ‘Stop!’” Abdelkader told the court. Mohammed got out, and Abdelkader parked nearby. “All of a sudden,” Abdelkader said, “I see my brother go by,” on the scooter. Later, Mohammed told him that he’d seen the TMAX parked with the keys in the ignition, and that “an opportunity like that doesn’t come around twice.” “My little brother was really excited,” Abdelkader recalled. “People from the bourgeoisie can’t understand it, but when you steal something, your adrenaline really gets going.” He said he’d been angry with Mohammed—to steal was haram—but not shocked. “Unfortunately, it’s not something unusual where we’re from,” Abdelkader said.

If he was indeed his brother’s accomplice in the motor scooter theft, one of his lawyers told the court, “Abdelkader Merah is the stupidest terrorist on the planet.”

Abdelkader’s lawyers noted that the police had found no witnesses to testify to their client’s presence at the theft. Had he not mentioned it to investigators, they likely never would have known he was involved. If he was indeed his brother’s accomplice, one of his lawyers told the court, “Abdelkader Merah is the stupidest terrorist on the planet.”

Even if Abdelkader’s active participation in the theft could be proved, this could not be deemed the act of an accomplice to murder unless it was shown that he knew what his brother planned to do with the stolen scooter. The prosecutor, Naïma Rudloff, dispensed with this issue by reminding the court that Abdelkader was a jihadist like his brother, and that, consequently, he necessarily understood his brother’s intentions. “Obviously,” she said, “none of what happened can be explained if we’re not in a jihadi context.”

Rudloff and the plaintiffs’ lawyers frequently took this inductive line of argument still further. If evidence of Abdelkader’s involvement was scant, they maintained, this was because he and Mohammed had sought to hide his involvement; the absence of evidence was proof, in itself, of guilt. The exotic term they invoked to mask the fallaciousness of this logic was taqiyya. Taqiyya is an Islamic precept that permits Muslims, when in danger or under duress, to conceal their true beliefs, breaking the usual injunction against lying. In the Muslim world, the termtypically refers to a practice among Shiites living in majority-Sunni areas, not one among Sunni jihadists, but non-Muslim Westerners sometimes present it as a sort of general doctrine of Islamic deception. (Taqiyya is, unsurprisingly, a favorite of the bigots and conspiracy theorists who speak of a global Muslim plot to subvert Western society from within.)

“The question that arises is whether or not we ought to believe you,” an attorney for the plaintiffs told Abdelkader. “If we’re to believe you, you’re in the car, your brother says to stop; he goes off to steal the TMAX, and you don’t see a thing?”

“Then don’t believe me about being present for the theft in the first place,” Abdelkader replied flatly from the glass box.

“You know that this scooter is going to be used for criminal acts that are perfectly aligned with radicalism!” the lawyer charged.

Abdelkader was suddenly agitated, and he retorted, “What’s ‘radical,’ what’s a ‘radical Muslim’?”

“You’re not a radical Muslim?” the lawyer asked in mock surprise.

“You say I’m a radical Muslim, so you must have some expertise in Islam?” Abdelkader was nearly yelling now. “What are the six pillars of Islam?”

Sunni Muslims typically recognize only five pillars of Islam; it is only jihadists who speak of six, adding “jihad” to the traditional list. If Abdelkader had been practicing taqiyya, he wasn’t very good at it.

Later, a lawyer for the plaintiffs asked Bernard Squarcini, the director of the DCRI at the time of the killings, why Mohammed claimed to have acted alone. “Does the fact that you don’t reveal who your accomplices are mean that you have no accomplices?” the attorney asked.

“No,” Squarcini explained. “It means you’re trying to protect them.”

In five weeks in the salle des assises, I encountered almost no one who seriously believed that Abdelkader might be acquitted, however limited the evidence against him. This was not because the taqiyya argument was widely accepted, though it did appear to be; and only a handful of the most cynical lawyers and journalists spoke of political interference or reason of state. Rather it was understood that Abdelkader’s conviction was assured because he was being tried not only as an accomplice in Mohammed’s crimes but also on a charge of association de malfaiteurs terroriste, or, loosely, “terrorist criminal association.”

In the summer and fall of 1995, Algerian Islamists killed eight people and wounded 200 more in a series of bombings in Paris. The following year, the French legislature passed a law to facilitate the charging of would-be terrorists before any such violence could be committed again. The association de malfaiteurs terroriste statute remains the primary tool of counterterror magistrates today. Its language is notoriously abstruse, but in essence the law goes beyond outlawing terrorist violence, per se, to punish the intent to commit it. In order to win an association conviction, prosecutors are not obliged to demonstrate the existence of any specific plot, only the broad contours of a hypothetical one. They must show that defendants intended to commit murders, for instance, but are under no obligation to show who the defendants intended to kill, or when, or how. In practice, prosecutors must show only that defendants hold violent ideologies, and that they associate with one another in suspicious ways. The premise of the law is that, under such conditions, the most reasonable explanation for their association is a terrorist plot. “We don’t have direct proof,” a prosecutor once explained to me. “We have proof through an intellectual construct.”

Civil libertarians have long argued that association de malfaiteurs terroriste criminalizes ideas. France has never taken such criticisms particularly seriously, much as it has refused to entertain challenges to its law against Holocaust denial. As with much of continental Europe, France’s politics is shaped by the memory of the twentieth-century catastrophes propelled by once-marginal ideologies, and the French, who have never had particularly strong speech protections, have few qualms about banning the most repugnant views.

Thousands of Islamists have been arrested and many hundreds convicted under the association law, and French security and intelligence officials long hailed the statute as the reason that since 1995 not a single Islamist attack had been carried off on French soil. Mohammed’s killings ended the 17-year run.

Though the association law was meant to be preventive, since those killings it has been repurposed to charge the alleged participants in successful terror plots, as well. In addition to attempting to prove that Abdelkader had been directly involved in his brother’s murders, then, the prosecution sought to establish that Abdelkader had joined with his brother in a terrorist association. He was a jihadist ideologue, they held; he spent time with Mohammed in the period before and during the killings; and he knew Mohammed to have been a jihadist ideologue as well. Abdelkader made little effort to deny the first two of these claims, and the prosecution therefore expended the greatest part of its energies in attempting to prove that Mohammed’s extremism was flagrant, and that Abdelkader was therefore necessarily aware of it.

This was an odd strategy, given that Mohammed had succeeded in passing himself off as a non-jihadist even to the French intelligence services. In November 2011, four months before the murders, two agents had come to Toulouse from Paris to meet with him and evaluate him as a potential informant. “He claims a moderate practice of Islam,” they reported in a subsequent intelligence note, and “does not share extremist and jihadist ideas.” They deemed Mohammed “quite clever and open” in addition to being “very polite.” His recruitment was marked down as “plausible.”

The prosecution called various witnesses from Les Izards—friends and acquaintances of the Merahs, men and women, young and old—to testify to Mohammed’s overt extremism. The charging document claimed that “most of the people from the neighborhood” had known Mohammed to be an Islamist radical. Yet their court testimonies did not bear that out.

“In my head, he wasn’t a Salafist, fundamentalist, jihadist, or anything like that, no,” one middle-aged woman, Touria Labiad, told the court. “For me he was just Mohammed.” Mohammed’s neighbors said they’d always found him to be “normal,” unremarkable, a delinquent like many others from Les Izards.

In the charging document, the brothers Bodief and Nasser Bougherara had been identified as “the most objective” of Mohammed’s acquaintances, and the court thus expected them to break with their neighbors’ claims of Mohammed’s normalcy. Bodief, a 41-year-old car-thief-turned-mechanic, arrived wearing black jeans and a black T-shirt with a large skull and crossbones on the front. He was a burly, grimacing man and did not seem to like being in court. Bodief had worked alongside Mohammed for several years at an auto shop owned by Nasser, and in 2012 he had given a lengthy statement to the police. The president asked him to summarize that statement for the court. “I don’t remember anymore,” he replied. The president asked what he meant. “I don’t remember anymore,” he said. “It means what it means.”

“You’re going to change your tone immediately,” the president snapped.

“I’ve told you three times now, I don’t remember!” Bodief said.

In fact, he did, and once his distaste for the court had registered with everyone in it, he said that Mohammed had been “impulsive” and “hotheaded,” but that this hardly distinguished him from his peers. “He was just a young guy, he just wanted to have fun more than anything else,” Bodief said. “The boy was never dangerous,” he added, and the plaintiffs’ lawyers were suddenly outraged. “The ‘boy!’’ one of them shouted. “He’s got holes in his memory except when it comes to singing the praises of Mohammed Merah!”

Later, I followed Bodief outside and found him smoking a cigarette on the courthouse steps. He was friendlier than he’d been on the stand. Abdelkader had a “nasty look” about him, he said, but Mohammed hadn’t been that way. “He was a good kid,” he told me with a shrug.

Nasser, Bodief’s 48-year-old brother, was a compact and more polished-looking man. He came to court in a cap, sport coat, and black brogues. But he was no less prickly on the stand. Mohammed, he said in a brief opening statement, had been “a kid from a bad neighborhood who wanted a shot, like others do.” Les Izards was a hard neighborhood—“a free-range zoo”—but if Mohammed had been radicalized, it was neither the neighborhood nor Abdelkader that had done it. Mohammed was “a kid who went completely off the rails,” Nasser said. “And in my opinion, he went off the rails all alone.”

This contention appeared to be to no one’s liking. Investigators had at one point suspected Nasser of a role in funding Mohammed’s attacks, and though this proved to be false, the president questioned him as if he were still a suspect. He asked about a withdrawal of 5,000 euros from his business’s bank account. “I work hard and pay my taxes!” Nasser said.

An important function of the trial was to indict the violent norms and low expectations of Les Izards, here conflated with jihadism, that led them to miss the threat Mohammed posed.

A lawyer for the plaintiffs presented a printout of a photograph that had been found taped to the door of a cabinet in Nasser’s garage. It showed the weathered face of an old man in a black turban with a bushy beard and a dagger between his teeth. The photograph wasn’t accompanied by any Islamic texts or political statements, and its style was more National Geographic than jihadist-propagandist, but the man appeared to be a Taliban fighter. Why, the lawyer asked Nasser, was this photograph hanging in his garage? Nasser was angry and silent, and when the lawyer pressed him again, he responded simply, “I believe in one thing: work.”

One important function of the trial was to indict the neighborhood and the way everyone in it lived, the violent norms and low expectations, here conflated with jihadism, that led them all to miss the threat Mohammed posed. Nasser seemed to have grasped that, and he left the stand in a silent rage.

I followed him out. “Can I bother you?” I asked. “No,” he said, not stopping. I asked if I might come to see him in the neighborhood. “Don’t come to Les Izards,” he said. “It won’t go well for you.”

Zoulikha Aziri, the Merahs’ mother, appeared late in the trial to testify. She tottered to the stand in the center of the court in a formless robe and a tasseled yellow hijab that accentuated the almost complete circularity of her face. She looked more defiant than solemn, her features turgid with angry confusion. The president explained to her that, because she was the mother of the accused, the law exempted her from swearing an oath of honesty. “Which does not prevent you from speaking with candor,” he added. “Yes, yes, yes,” she said.

She made a brief opening statement, in hesitant French. “I think my son Abdelkader is innocent, he has nothing to do with the whole story that happened,” she said. “Mohammed—what hedid, Mohammed, it’s very, very serious. I didn’t know what he was going to do. He did what he did; now he’s dead.” A translator had accompanied her to the stand, and Aziri turned to the young woman to assist her with a brief word for the plaintiffs. “I present my apologies to the victims,” Aziri said. The president then questioned her about her life.

She was born in 1957 in a village in what was then French Algeria, the eldest of six children. She raised her siblings and received no schooling, according to an account she once gave to social workers. At 18, she was married without her consent to a man she had never met, selected for her by her stepfather. Her new husband, Mohammed Merah, was 15 years her senior and already married to a second woman, with whom he had several children. He worked in a factory in France, and Aziri followed him there in 1981, with her two children, a daughter, Souad, and a son, Abdelghani. A first daughter had died in Algeria, as an infant. It had been a sickness, Aziri thought, or perhaps her mother-in-law had poisoned the baby. “I don’t know,” she told the court dully.

Aziri arrived in the housing projects of Toulouse speaking not a word of French. She rarely left her apartment. By 1982, two more children had been born, a daughter, Aïcha, and another son, Abdelkader. Aziri apparently wanted no more. According to one social worker’s report, another Algerian woman told her of the existence of contraceptive pills, and she began taking them, although apparently without understanding how they worked. Mohammed was born in 1988.

Aziri’s husband beat her, and sent his earnings back to his other wife in Algeria. In 1992, she fled with her children to a women’s shelter, and a divorce was completed several months later, at which point whatever stability the family may have known seems to have evaporated. Aziri’s brother, who lived in Toulouse, imposed himself as a malignant patriarch, hectoring and beating his sister and her children. Her eldest son, Abdelghani, began drinking heavily; he too beat his mother and his siblings, especially Abdelkader, who was flagged by social workers as a “child in danger” as early as 1995. Various testimonies suggest Abdelkader was raped by an uncle, as well. As he grew older, the middle brother exhibited a distinct sadism and was once alleged to have tied Mohammed to a bed by his wrists and ankles and beaten him for two hours with a broomstick. For most of his childhood, Mohammed would be in and out of group homes, where he could be protected from his brother. Abdelkader beat his older sisters if they smoked or stayed out late; he beat his mother, too, and she took to locking herself in a bedroom when he was home.

Mohammed attacked his mother as well. In 2002, when he was 13, his middle school principal wrote to a judge that Aziri had come to her with “several marks on her face and numerous bite marks on her arms.” Mohammed was apparently no longer sleeping, and spent his evenings terrorizing her. “He’s crazy,” his mother told the principal. Mohammed was placed in another group home.

That same year, after punching a social worker in the face—the woman had accompanied Mohammed and Aziri to a court date, and he grew angry after his mother reacted unfavorably to the prospect of having him back at home—he was evaluatedby a court-mandated psychologist. “Mohammed Merah’s discourse shows no sense of guilt,” the psychologist wrote. “He does not imagine the repercussions of his acts on the person he assaults because he places himself in a position of victimhood.” He had told her, “For adults it’s ‘violence,’ but for me it’s self-defense.” He was frequently sad, he reported—social workers indeed often found him crying, even as a teenager—and he sometimes thought of suicide. (In 2008, while in prison, he tried to hang himself.) The psychologist reported that his mother showed no understanding of her son’s behaviors, no notion of the forces that might be driving them. She was unwilling, probably unable, to interrogate the norms by which she and her family lived. Aziri showed “little capacity for mental elaboration,” the psychologist wrote, and “little self-awareness.” The events of her life were so unremittingly grave as to fail to register in her as serious at all.

In court, she lied about them. Her relationship with her ex-husband had been “a normal relationship,” she said, and she denied that he had ever beaten her. The president asked if Abdelkader had been violent when he was younger. “Abdelkader? Abdelkader normal,” she said.

“You’re sure?” the president asked.

“Sure,” she replied. The president read from a social worker’sreport, describing Abdelkader’s violence. “No, no, no,” Aziri said. She was asked if, in light of the violence, her family was perhaps not entirely normal. “Of course it’s normal,” she insisted. It was pointed out to her that her sons had committed a great number of violent acts, including murder. “There is no problem in the Merah family,” she said. “We’re not animals!” She denied having spoken to the police after Abdelkader tied Mohammed to the bed. The president read aloud from her statement from the time; she denied having given it.

The president turned to another line of questioning. Mohammed had lured his first victim to the site of his murder by claiming to want to buy his motorcycle, which the man, Imad Ibn-Ziaten, had put up for sale on the internet. (In his listing, Ibn-Ziaten had identified himself as a soldier.) Several days before the killing, shortly after eleven in the evening, someone had connected to the online classified from within Aziri’s apartment. Investigators suspected that it was Abdelkader who viewed the advertisement that night, and if this could be proved, his complicity in his brother’s killings was patent.

From the start and throughout the five years of the investigation, Aziri had maintained that Mohammed did not come to her apartment that night. She acknowledged that Abdelkader had been present earlier in the evening, but said he had left several hours before the connections were made. And yet Abdelkader’s cell phone pinged a cell tower near his mother’s apartment at the time of the connections, and the alibi he initially provided for his whereabouts that night—he claimed to have been at a party—proved false.

In court, Aziri denied that either of her sons had come to her apartment that night. “I was alone,” she said. “There was no one there!” Mohammed must have made the connections from outside her apartment, she said, by Wi-Fi. She was reminded that investigators had found that Ibn-Ziaten’s ad had not been accessed over Wi-Fi but via the hardline internet connection inside her apartment. “For me, what your technicians said isn’t true,” she declared.

To watch Aziri flail and fight and simply refuse to be honest was to resign oneself to the conclusion that she, and whatever knowledge she had of the crimes, was beyond reach.

It was incomprehensible, given the ease with untruth that she’d already demonstrated, and the lack of legal consequences, that she did not simply lie and say that she now remembered that Mohammed had come to her apartment that night, that it must have been him and not Abdelkader. This would have made clear that, if the court and plaintiffs and country were to be deprived of the information she possessed, it was out of a maddening but comprehensible desire to free her surviving son from prison. But reason seemed to have no purchase on her; her obstinacy was pointless. To watch her flail and fight and simply refuse was to resign oneself to theconclusion that she, and whatever knowledge she had of the crimes, was beyond reach.

A lawyer for the Ibn-Ziaten family stood to make his own attempt.

“Madame, this family wants to know the truth,” he said.

“That’s normal,” Aziri said, almost sympathetically.

The lawyer explained once again that whoever made the connections was necessarily inside her apartment.

“Mohammed took the codes and connected from outside,” Aziri said through the translator.

“That’s not possible!” the lawyer yelled. “There was someone at your apartment! The Ibn-Ziaten family has the right to know!”

“No one! There was no one at my apartment!” she shouted, switching now into rapid French. “Abdelkader isn’t there! Why are you speaking to me like this?! Me, too, I can speak to you like this!” Abdelkader reached a hand through an opening in the glass box and motioned to his mother to calm down.

“The families have the right to know the truth!” the lawyer yelled. “They’ve been waiting for it for five years—five years!”

Abdelkader’s lawyer, Éric Dupond-Moretti, stood and began to bellow across the aisle of the court. “What has she done?” he demanded. “What are you accusing this woman of?” The courtroom went nearly silent. “Of lying? And so what? She’s the mother of the accused, and she’s the mother of a dead man!”

The courtroom erupted. From the rear, a young man, IbnZiaten’s younger brother, screamed at Dupond-Moretti. “You’re not ashamed?! Shut up! Shut up!” he shouted through tears. “You’re a murderer! You’re mean! You’re shit!” He stumbled from the courtroom.

Dupond-Moretti had been wildly indecorous, and his words evidently set off the outpouring of the man’s anguish, but I do not think they were its source. The man’s deepest grievance, of course, was with his brother’s killer or killers, and the mother who was evidently shielding them. But I suspect it was also with the contention, which had been peddled to him since the days after the murders and throughout the five years that followed, that Mohammed’s radical evil had been fomented and then abetted by Abdelkader, and that a trial would prove it, and that it was thus possible to grant the victims the tidy moral resolution they deserved. What the events of the trial instead demonstrated was the cruel inadequacy of this contention, the naïveté of this logic. The most terrible discovery for anyone who watched the trial closely and was willing to plumb his own sense of disorientation was that the Merah family inhabited a corner of the world where logic of this sort simply did not hold.

Throughout the trial, I often shared a bench in the salle des assises with an anthropologist named Ariel Planeix. Planeix had been recruited by the French Ministry of Justice to produce an internal study on the lives of several dozen “radicalized” minors, some of whom had been before the courts, and others whose cases were handled by social workers. The upheaval and trauma of the Merahs’ lives were essentially average among the cases he’d seen, he said. He viewed Mohammed as a template for the generation of jihadists that has emerged since his killings. “He’s the new face of a sort of reactive violence,” he told me, violence that is politicized but that is hardly rooted in politics. The minors Planeix studied had all been abused, abandoned, or raped, and sometimes all three; if they remained in contact with their families, their families systematically denied the existence of any such problems. Their childhoods, like the Merahs’, were an almost absurd cumulation of horrors. A growing body of research suggests that, among this new generation of jihadis, this is indeed the norm. This is not to suggest that jihadism is merely a social problem, but rather that “radicalization” is much more than a matter of ideology and its transmission.

This ought to be a source of reassurance. Radicalization is not the vast crisis it has often been made out to be in the West, and certainly not an existential threat; it seems to operate upon a very particular population, and that population is small, damaged, and profoundly marginal. It is the great luck of the Salafi-jihadis that that their Islamic mythology should hold appeal for these men at the terrible margins; it is their great luck, too, that European societies should be so confounded by these men, torn between their loathing for them and a buried guilt for the outrages to which they, in their marginal lives, are exposed. Beneath the anger and horror at every jihadist attack in Europe is, like a shameful, postcolonial secret, an unsung note of self-reproach. Shame, like fear, is only very rarely a spur to sober evaluation of the problems at hand. But it is easier to overcome.

Abdelkader’s lawyers argued his right to think and believe as he saw fit. They were no more interested in an examination of how or why he’d chosen his particular path than was the prosecution. The trial served, then, as much as anything, to perpetuate Abdelkader’s own myth about himself, as a man defined by his extreme convictions, a sort of empty vessel filled, by divine providence, with jihadist Islam. This was a myth that was almost entirely palatable to his accusers, absolving them as it did of the uncomfortable responsibility of looking closer. The myth of pure evil flattered all. The court ostensibly scrutinized Abdelkader, his family, his neighborhood; but it seemed to see only what it wished, or what Abdelkader wished, in each of them.

“Do you have anything to add to your defense?” the president asked Abdelkader on the final morning of the trial, turning to the glass box.

“Yes, Monsieur le Président,” Abdelkader said blandly. He stood to speak. “I said it before and I’ll say it again: I have nothing to do with the killings committed by my brother.” He had finished his statement.

In the evening, the president read out the judges’ verdict, accompanied by an explication of the logic by which they had concluded that Abdelkader had not been shown to be his brother’s accomplice, but that he had participated in “a terrorist grouping or agreement” with him nonetheless. The Merahs’ association aimed to commit killings, the judges wrote, and this intent was revealed “precisely” by the killings Mohammed committed. Abdelkader was sentenced to 20 years.

There can be little doubt that Abdelkader Merah is a very dangerous man, and I suspect that everyone in the courtroom was relieved to see him convicted. But it was a glorious day for no one. Abdelkader sat unmoved in the glass box. In the end it was the prosecution itself that chose to appeal, finding the partial conviction insufficient.